Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a nacelle, one or more rotor blades, a gearbox, a generator, and a power converter. The rotor blades capture kinetic energy of wind using known airfoil principles. For example, the wind turbine may include one or more pitch drive mechanisms configured to pitch the rotor blades into the wind. As such, the rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy, which is fed into a utility grid via at least one electrical connection. A power converter is typically used to convert a frequency of a generated electric power to a frequency substantially similar to a utility grid frequency. Conventional wind turbines also typically include a main controller to control various operational modes of the wind turbine.
The controller is typically configured to receive key signals that indicate readiness of the wind turbine to generate power and send commands to the power converter. More specifically, the controller may receive a plurality of signals from the power converter and/or other components of the wind turbine over dedicated interfaces. Such signals may include a “ready-to-run” signal, a “run-ready” signal, a “reactive-power-no-wind (RPNW) run-ready” signal, or similar, all of which indicate the readiness of the wind turbine to produce real or reactive power. It should be understood to those having ordinary skill in the art that such signals may be referred to herein interchangeably. Before the controller commands the power converter to generate power (i.e. run), a predetermined set of conditions must first be satisfied. For example, one of the necessary operating conditions that is required for assertion of the run-ready signal is a predetermined rotor speed, e.g. typically between minimum cut-in speed and a maximum cut-out speed. The inventors determined, however, that much time was wasted by spinning up the rotor to the predetermined speed only to find that one or more other readiness conditions had not been satisfied, thereby preventing the run-ready signal to appear (i.e. preventing startup of the power converter).
Accordingly, a system and method that addresses the aforementioned problems would be welcomed in the technology. For example, a system and method that incorporates a “spin-ready” signal would be advantageous. More specifically, the spin ready signal requires only a subset of the ready-to-run conditions and indicates a high likelihood that spinning-up the rotor will allow the power converter to generate power.